The advantage of incorporating a horizontal flow path, as opposed to a vertical upward flow path, when using the force of gravity to separate oil, water and gas into disparate laminar layers is well known. With a vertical upward flow path the upward momentum presents a directly opposing force to the force of gravity, thus impeding the separation of the fluids much more than the resistance to the separation that is imposed when the flow is moving horizontally. To accomplish the horizontal flow path the containment vessels utilized are generally of an elongated horizontal cylindrical configuration with a length to diameter ratio exceeding 3:1 and with fluids stratified in relatively thin layers. This is a very efficient arrangement when the vessels are anchored and level but has the disadvantage of a minor longitudinal tilting causing the upper and the lower strata's to be pinched into a wedge shape that can greatly reduce the volumetric capacity allotted to a particular fluid and can cause misdirection of the various fluid flows.
This invention introduces a containment vessel that is configured to attain the processing advantages of the horizontal flow path relative to gravity separation while allowing for a severe tilting of the vessel without significantly changing the geometry of the fluid containment spaces or causing a misdirection of the fluid flow paths.